Method of producing aligned acrylonitrile polymer filament yarns



y 968 CHOZO NAKAYAMA ETAL 3,384,694

METHOD OF PRODUCING ALIGNED ACRYLONITRILE POLYMER FILAMENT YARNS FiledNov 12 1964 United States Patent 3,384,694 METHOD OF PRODUCING ALIGNEDACRYLO- NITRILE PGLYMER FILAMENT YARNS Chozo Nakayania, Teiichi Kaku,Hiide Aizawa, and Takeaki Iwamoto, Fuji-shi, Japan, assignors to AsahiKasei Kogyo Kabushiki Kaislla, Osaka, Japan, a corporation of JapanFiled Nov. 12, 1964, Ser. No. 410,687 Claims priority, applicationJapan, Nov. 21, 1963, 38/ 62,275 10 Claims. (Ci. 264-290) ABSTRACT OFTHE DISCLOSURE A method for producing well aligned acrylonitrile polymerfilament yarns in which the filament yarns are prepared by wet spinningof acrylic polymer which comprises impregnating heated, stretched andswollen filament yarns with an oiling agent having a melting point below100 C., or 2% or less of a sizing agent with respect to the weight ofthe filament yarns, or a mixture of said oiling agent and 2% or less ofsaid sizing agent, drying the impregnated yarn in a dryer whilesubjecting same to 5-20% shrinkage in the direction of the filamentlength, impregnating the dried filament yarns with or less of a sizingagent with respect to the weight of the filament yarns, and drying samewhile subjecting it to 010% stretching in the direction of the filamentlength.

This invention relates to methods of producing multiplefilament yarns.

The expression acrylonitrile polymer filament yarns or the like ashereinafter used in this text means such products as are made of apolymer comprising acrylonitrile units alone or at least 85 percent byweight of acrylonitrile units and at most percent by weight of units ofat least one monomeric olefin which is copolymerizable withacrylonitrile.

The expression acrylic filament yarns when same hereinafter appears isto be construed as acrylonitrile polymer filament yarns, which latterterm appears in the claims and which is defined in the precedingparagraph.

It is well known that certain mechanical properties of acrylic-fiberssuch as brittleness can be improved by relaxing the fibers such as by ashrinking treatment. However, in the wet spinning of acrylic filamentyarns, attempts to effect shrinking treatments are accompanied by agreat deal of trouble.

In the production of filaments of small total denier, it is advantageousto treat as many filament yarns as possible while moving them inparallel to one another with relatively small spacing therebetween andto take them up in an untwisted state. This brings about economicadvantages such as an increase of production per unit floor space and areduction of installation costs.

Accordingly, it has been found desirable to extrude a solution ofacrylic polymer, through a plurality of spinnerets each of which hasmany small holes, into an aqueous coagulant to precipitate the polymerinto fibrous form. A plurality of monofilaments are made into a unit offilament yarn at each spinneret, and a minimum distance between units ismaintained. The technique further involves subjecting the fibers towashing, and then to heat stretching, and subjecting them simultaneouslyto drying and shrinking in a drier while maintaining the fibers .in asubstantially tension-free state.

However, when the shrinking treatment is effected fuzzing and breakingare induced. Further, as the moisture content decreases due to thedrying, the individual filaments separate from each other due tomechanical vi- 3,384,694 Patented May 21, 1968 bration and anelectrostatically repulsive force which results therefrom.

An object of the present invention is, accordingly, to provide animproved method of producing acrylic filament yarns wherein the filamentyarns are maintained in good alignment and remain in an untwisted stateand wherein many filament yarns can move in parallel to each other witha very small spacing therebetween and can be subjected to a shrinkingtreatment without inducing the above-mentioned disadvantages.

In accordance with the present invention, there is proposed a wetspinning of acrylic filament yarns wherein swollen fibers, which havebeen stretched by heating, are impregnated with an oiling agent whichhas a melting point lower than 100 C. and which is preferably a liquidat room temperature. Alternatively, the swollen fibers can beimpregnated with less than 2 percent by weight and preferably less than1 percent by weight of a sizing agent or a mixture of theabove-mentioned oiling agent and the sizing agent. The swollen fibersare then heated at 100 C. to 200 C., and preferably at 100 C. to 180 C.,in a drier in which drying and 5 to 20 percent shrinkage in thedirection of the fiber axis are effected. Subsequently the fibers aretreated with an aqueous solution of a sizing agent such that it adheresto the fibers in an amount less than 10 percent by weight of the fibers,the fibers being maintained under tension to obtain a stretching of from0 to 10 percent in the direction of the fiber length which does notexceed the shrinkage afforded in the aforementioned shrinking treatment.The filaments are then heated at a temperature lower than that of theprevious drying and shrinking treatment (e.g., from C. to 120 C., andpreferably from C. to 110 C.) and are dried in a manner such that thefilaments have a high resistance to stretching and can sustain a hightension load.

In general, when hot-stretched swollen fibers are subjected to dryingand shrinking in a big tow, it is a com mon practice to dry them firstat a relatively low temperature or at a high temperature under tensionto render the fine structure of the fibers denier and then to shrinkthem at a high temperature under either dry or wet conditions. If anattempt is made to dry and shrink the fibers simultaneously by heatingat a high temperature, the temperature inside the fiber bundle iselevated before the losing of water therefrom and devitrification of thefibers frequently results. However, in the case of small fiber bundlessuch as in the case of filament yarns, it has been discovered thatdevitrification surprisingly does not occur if the swollen fibers areimmediately heated to a temperature higher than C., hot air beingemployed as the heating medium and humidity being suppressed to about0.1 kg. of water per kg. ofdry air.

Due to this discovery, it has become possible to put the presentinvention readily intotpractice. The reason why the foregoing treatmentmeets the purpose of the present invention will be explainedhereinafter.

In order to dry the swollen hot-stretched fibers and provide themsimultaneously with from 5 to 20 percent shrinkage in the direction oftheir length, the filament yarns must be maintained in a substantiallytension-free state in the drier. A violent shaking of the filament yarnsdue to vigorous agitation by the hot air under these circumstancescannot be avoided. However, increasing the distance between the filamentyarns to avoid the contacting of filaments is disadvantageous from aneconomical viewpoint. To solve this problem, the idea has beenconaidered of placing combs across the direction of movement of thefilament yarns to reduce the con-tact of the filament yarns as much aspossible. However, this idea cannot be used with filament yarns whichhave not been impregnated with the aforesaid oiling agent, sizing agentor a mixture thereof, for when the filament yarns are dried andsubjected to shrinkage without the impregnating treatment, the filamentyarns disassemble into their constituent monofilaments, due tomechanical vibration and electrostatieally repulsive forces, and themonofilaments are broken by contact with the combs and fuzzing isinduced.

If, however, the filament yarns are impregnated with 2 to percent byweight or more of a sizing agent based upon the weight of fibers, theseparation of the monofilaments clue to drying can be prevented. But thefilament yarns must not contact the combs before sufiiciently drying, orelse the sizing agent on the surface of the filaments will stick to thesurfaces of the combs which are heated to a high temperature and thereis then formed a rough surface which increases frictional resistancebetween the filament-s and combs, thereby causing fuzzing and breakingof the filament yarns. Even if the treatment could be effected withoutcausing fuzzing and breaking, dried sizing agent precipitates andsolidifies on the surfaces of the combs, which gradually grow in sizeand ultimately become obstacles for filaments to pass through. As aconsequence, the treatment cannot be continued for a long time.

When an oiling agent alone is impregnated into the fiber yarns, theseparation of monofilaments due to drying can be prevented, thefilaments remaining almost free from damage due to the lubricatingeffect of the oiling agent and being thus able to endue the simultaneousdrying and shrinking treatments. However, in this instance, the onlyforces which maintain the alignment of the filament yarns are theviscosity and surface tension of the oil, and there are no otherpositive adhering and clinging properties available. As a result, whensuch filament yarns are supplied as untwisted yarns, mono'filaments willbe separated and damaged during weaving and knitting.

For the foregoing reasons, the method of the invention is best forsubjecting filament yarns, which are swollen and oriented by heating andstretching in a wet spinning process, to a simultaneous drying underheat and shrinking from 5 to percent in the direction of the fiberlength in a substantially tension-free state While moving the filamentsin parallel at a minimum spacing and for providing filament yarns whichare untwisted and well aligned and adapted to be maintained in suchstate through preparatory operations for weaving and knitting.

The practice of the present invention will be more fully explained asfollows:

The first step involves heating swollen fibers, which are oriented byhot stretching in a wet spinning process and which are moving in closelyspaced relation and in substantially tension-free condition, to effectdrying and simultaneously to shrink the same in the direction of lengthup to from 5 to 20 percent. In connection with this step and to maintainthe filament yarns in good alignment, the filaments are impregnated withan oiling agent having a melting point lower than 100 C., and preferablyan oiling agent which is in liquid state at room temperature.Alternatively, there can be employed less than 2 percent by weight of asizing agent, and preferably less than 1 percent thereof, or a mixtureof such sizing and oiling agents. The drying temperature used in thisstep is from 100 C. to 200 C. and preferably from 110 C. to 180 C. toobtain the desired shrinkage of from 5 to 20 percent. The oiling agentis used either by itself or in the form of an aqueous emulsion, but itsmelting point must be lower than 100 C. to prevent the oil from stickingto combs which are installed in the drier and from precipitating theretoas a solid. For facilitating impregnation, it is preferable to use anoiling agent which is liquid at room temperature.

Oiling agents useful for the impregnation treatment have no restrictionexcept as to melting point. Various kinds of commercially availableoiling agents which contain cationic, anionic, amphoteric, or non-ionicsurfactants are useful. However, when the impregnation treatment is 4 papplied to undried wet fibers, as in the case of the present invention,oiling agents containing ionic surfactants are not suitable because theyimpart an unfavorable effect with respect to dyeability. For example,when the fibers are made with acrylic polymer produced by copolymerizingacrylonitrile with a monomeric olefin, which is copolymerizaible withacrylonitrile and contains an acidic radical such as-sulfonic acid orcarboxylic acid for the purpose of rendering the fiber-s dyeable, atreatment with a cationic surfactant reducesthe affinity of the productto basic dyes and a treatment with an anionic surfactant increases theaffinity of the product to basic dyes. This will constitute no problemfor those skilled in the art; however, the use of an oiling agentcontaining a non-ionic surfactant is generally preferable.Polyoxyethylene alkyl ethers such as Actinol R400, Noygen ET- and thelike, polyoxyethylene alkylphenols such as Noygen K, Elenon 20 and thelike, polyoxyethylene alkyl esters such as Em alox S, Brian L 200 andthe like, sorbitan alkyl esters such as Nicols SL and the like or othernon-ionic surfactants such as Pronon 104, Tornenolin F and so forthafford good results when they are used to adhere in an amount of from0.5 to 2 percent by weight based upon the weight of the fiber. It is tobe understood that the foregoing non-ionic surfactants and the appliedamount are merely illustrative and do not limit the scope of theinvention.

The sizing agent used to impregnate the filament yarns before the dryingand shrinking treatment is not necessarily a special one. The samesizing agents as used after the drying and shrinking treatment willgenerally serve the purpose. However, the amount of sizing agent to beimpregnated is important, for it has been determined that when theamount is less than 2 percent and preferably lower than 1 percent byweight, the above-mentioned troubles due to stickiness are notencountered.

When a mixture of oiling and sizing agents is used for impregnating thefilament yarns before the drying and shrinking treatment, there is norestriction as to their combination. The kinds of sizing agents usefulin this instance will be illustrated hereinafter.

In performing the simultaneous drying and shrinking treatment, it isdifficult to set a definite restriction as to the temperature of thedrier. Even at a temperature as low as C., it is possible to produce theshrinkage required. However, the attainable upper limit of shrinkage isrestrictive and the length of drying at 100 C. is twice that whenheating is performed at C. Heating at a temperature higher than 200 C.is liable to cause heatdiscoloration of the fiber.

If the residence time in the drier is minimized for affording thedesired shrinkage while avoiding heat-discoloration at a temperaturehigher than 200 C., the unevenness of temperature distribution in thedrier and of air flow is liable to injure the homogeneity of thefilament yarns. Thus, such a treatment should be put into practice inthe case of filament yarns for which excellent homogeneity in quality isrequired. In this regard, the drying and shrinking treatment must beperformed at a temperature between 100 C. and 200 C. and preferablybetween 110 C. and 180 C. The residence time must be chosen so as tomake the moisture content of the fiber less than 5 percent by Weight.

The filament yarns provided with desired shrinkage while beingmaintained in good alignment and subjected to drying are, in the secondstep, treated so that there adheres thereto less than 10 percent byweight of sizing agent based upon the weight of fibers, the yarns beingstretched by from 0 to 10 percent at a temperature lower than that ofthe previous drying and shrinking treatment and then further dried undertension.

The sizing agent used in the present invention is selected from thosecommercially available as warp sizing agents. These sizing agentsinclude those of the polyvinyl alcohol type such as Gosenol GH-17,Gosenol GL-OS,

Gosecizer 8-100 and the like, those of the polyacrylic acid derivativetype such as Marbosol pp-20, Marbosol A-840 and the like, and those ofthe vinyl acetate maleic acid copolymer type such as Tamanori 5-400 andthe like, which are all useful for the purpose of the present invention.

These sizing agents are also merely illustrative and do not limit thescope of the invention. They can be used alone or in mixture. Ifrequired, it is possible to use them by mixing them with at least onekind of oiling agent which serves as the dispersing agent orimpregnating agent. It is one of the essential conditions of the presentinvention that the filament yarns be dried with less than percent byweight of the sizing agent under tension at a temperature lower thanthat of the previous drying and shrinking treatment so as to stretch thefiber by from 0 to 10 percent and to dry the same simultaneously. Aproblem to be considered in the drying of the sized filament yarns whichare moving in a closely spaced relationship is that the filament yarnsmust not contact anything else except air while drying and particularlywhile the surface of filament yarns are sticky. If contact betweenfilament yarns occurs, it is difficult to separate the filaments fromeach other without the damage due to strong cohesion. Unless combs beused to avoid contact of the filament yarns, the above-describeddiificulties cannot be avoided. The present invention solves this byeffecting the drying of filament yarns under tension. The vibration offilament yarns due to the disturbance by air is minimized by applyingmore tension to the filament yarns and by greatly increasing thedistance between combs which are installed transverse to the movingdirection of the filament yarns to prevent them from contacting eachother, Providing tension for the filament yarns can be accomplished bystretching the fitamcnt yarns. In connection with thermoplastic fibers,the force required to afford a definite proportion of stretching issmaller as the temperature is higher. Hence, the filament yarns arestretched at a low temperature if the stretching of the filament yarnsis to be minimized under as great a tension as possible.

In view of the foregoing, in the drying of a plurality of sized filamentyarns, it is important to stretch the filament yarns so as to afford astretching which is smaller than the shrinkage given to the filamentyarns in the previous shrinking treatment, and to select a dryingtemperature lower than that of the previous drying and shrinkingtreatment or particularly 80 C. to 120 C. and preferably from 90 C. to110 C. In this step there may be no combs installed in the drier.However, there may be combs installed if sufficient inter-teeth spacingis maintained so that the filament yarns do not contact until theirsurfaces lose their stickiness due to drying.

By the above method, it has now become possible to manufacture acrylicfilament yarns which are untwisted but are maintained in good alignmentwith a sizing agent and which possess excellent mechanical properties.Said method can be affected as a continuous run consisting of subjectingclosely spaced fiber filaments in good alignment to a simultaneousdrying and shrinking treatment during the movement thereof ,to take upin a wet spinning process, and then effecting sizing and drying again.

The nature of the present invention can be more fully understood byreferring to the accompanying drawings. FIG. 1 is a flow sheet of thepresent process. FIGS. 2 and 3 are partially enlarged views of a mass offilament yarns being separated individually by teeth of a comb fixed ina drying apparatus, FIG. 2 showing the case where the filament yarns aretreated with an oiling agent, a sizing agent or a mixture of the two,and FIG. 3 showing the case where the filaments are not treated at all.

In FIGURE 1, an acrylic polymer is dissolved in a nitric acid solventhaving 70 percent by weight concentration so as to form a percent byweight spinning solution. After de-aeration, this spinning solution issent to a spinning apparatus having 100 spinnerets per unit.

More particularly, the spinning solution is delivered from the dissolverto a pipe 2 at desired speed by a gear pump 1. At the end of the pipe 2there is provided a multiholed spinneret 3. The spinning solution isextruded from these fine holes into an aqueous coagulating bath 4 whichcontains 30 percent by weight of nitric acid and is cooled to atemperature of --3 C. Filaments 5 precipitated in fiber form are takenfrom the bath by a group of rollers 14 running at a peripheral speed offrom 5 to 10 meters/ minute and the fibers are spaced by a distanceranging from 4 to 10 millimeters. These filaments are led to a washingbath 6 where the solvent is completely removed, passed through a groupof rollers 15 which are running at the same speed as the rollers 14 anddelivered to a stretching bath 7 in which a liquid or steam is used as aheating medium. By causing a group of rollers 16 to run at a peripheralspeed at least 4 times as fast as that of the roller group 15, thefilaments 5 are stretched in the stretching bath 7 in their direction oflength by an amount at least 4 times their original length.

The wet, swollen filaments stretched by heating are impregnated with anoiling agent by contacting the filaments lightly with the upperperipheral surface of a roller which is running in the same or reversedirection as the direction of filament movement and the lower side ofwhich is immersed in an oiling bath 8. When the oiling agent is an oilhaving a melting point of lower than C. and is preferably a liquid atroom temperature, it is further desirous, as aforementioned, that theoil be a non-ionic surfactant. The oiling agent may be used by itself orin the form of an aqueous emulsion, but in general the use by itself ispreferable. It is not harmful to heat the bath 8 to a temperature lowerthan 100 C. If necessary, the amount of oiling agent adhering to thefibers can be made more than 2 percent by weight, but, for the purposeof the present invention, from 0.5 to 2 percent by weight is generallysufficient. The adhesion of an excessive amount of oiling agent weakensthe adhesive force of the sizing agent which is supplied in the nextoperation. As a practical matter, it is possible to determine the amountof oiling agent simply by experiment with the relationship between thecontact length of the filaments with the related roller and the relativespeed of filaments with respect to the roller surface.

When a sizing agent is used as the treating liquid, it can be in theform of an aqueous solution of a single substance or a mixture ofsubstances. The adhered amount is suitable when it is less than 2percent by weight and preferably less than 1 percent by weight relativeto the fibers. In general such an amount is especially practical for theshrinking treatment, where the shrinkage is as low as from 5 to 15percent. Further, in the following sizing operation, the sizing enablesreducing the concentration of sizing agent, and to perform the dryingafter the sizing under relatively low tension conditions by which theextent for reducing the effect of the shrinking treatment during thedrying operation can be minimized.

When a mixture of sizing agent and oiling agent is used as the treatingliquid, it is preferable to use an oiling agent dispersed in an aqueoussolution of sizing agent. The amount to be adhered to the fibers is thesame as when an oiling agent or sizing agent is used alone.

Filament yarns impregnated as above-described are afforded a desirableextent of shrinkage ranging from 5 to 20 percent in a drier 9 at atemperature of from 100 C. to 200 C. and preferably from C. to 180 C.within a controlled range of :5 C. Inside the drier 9 there are provided10 combs spaced 40 centimeters apart across the direction of filamentmovement. These combs prevent mutual contacting of the filament yarns.Desired shrinkage is imparted by groups of rollers 16 and rollers 17, ofwhich the latter run at a slower peripheral speed.

The filament yarns thus subjected simultaneously to drying and shrinkingtreatment, While maintaining a good alignment, are subsequently treatedin a sizing bath 10 which has the same construction as the bath 8 and isprovided with an aqueous solution of the above-mentioned sizing agentalone or a mixture of two or more such sizing agents in an amount torender the adhesion less than 10 percent by weight relative to thefibers. Then the filament yarns are given in a drier 11 a stretchingwhich is in the range from O to 10 percent in the direction of lengthand less than the extent of shrinkage produced in the abovementionedshrinking treatment and are dried under tension at a temperature of from80 C. to 120 C., and preferably from 90 C. to 110 C. Inside the drier 11no combs are provided within 2 meters of the inlet for the filamentyarns. By heating under tension as above-mentioned, the shaking offilament yarns is prevented as much as possible, and the drying iscontinued until the surfaces of the filament yarns lose theirstickiness. Thereafter, the drying is completed while preventing themutual contacting of the filament yarns by the use of combs.

If necessary, sized and dried filament yarns are impregnated withfinishing oil in a bath 12 and wound up on take-ups 13.

The gist of the present invention will be further understood bycomparing FIGS. 2 and 3. That is to say, when the filament yarns aretreated with an oiling agent, a sizing agent or a mixture of the twoaccording to the present process, and simultaneously dried and shrunk inthe first drier, the filament yarns remain well bundled as shown in FIG.2. However, the filament yarns subjected to no treatment as in thepresent invention are remarkably separated into single filaments asshown in FIG. 3, and hence it the filament yarn arranged at narrowintervals as in the present invention are treated, they will be readilycontacted with adjacent filament yarns to cause fuzzing or breaking.

EXAMPLE 1 An acrylic polymer comprising 91.5% by weight ofacrylonitri'le, 8% by weight of methylacrylate and 0.5% by weight ofsodium methallyl sul'fonate, was dissolved in a nitric acid solventhaving a concentration of 70% by weight so as to form a 15 by Weightspinning solution. After deaeration, this spinning solution was sent toa spinning apparatus having 100 spinnerets per unit, at a speed such asto form 75 denier filament yarns when the yarns were wound up at a speedof 60 m./min. The spinning solution was extruded from a nozzle of 26holes having a diameter of 0.08 mm. into an aqueous coagulating bathwhich contains 30% by weight of nitric acid and was cooled to atemperature of 3 C. Filaments coagulated in a fibrous form are takenfrom the bath so as to form a yarn with each spinneret and the yarnswere spaced mm. apart. These filaments were led to a washing bath wherethe solvent was completely removed, and delivered to a stretching bathin which steam saturated at atmospheric pressure was used as a heatingmedium. The filaments were stretched in the stretching bath to 7 timestheir original length.

The stretched, swollen filaments were impregnated with a treating liquidcontaining the following components. Sizing agent: Percent Polyvinylalcohol type Gosenol GL-SO (trademark of Nihon Gosei Kagaku Kogyo K.K.)1

Polyacrylic acid derivative type Marposol PP- 20 (trademark of MatsumotoYushi Kogyo K.K.)

Oiling agent:

Non-ionic surfactant of polyoxyethylene alkyl ethers Actinol R-100(trademark of Matsumoto Yushi Kogyo K.K.) 0.5

and the total amount of sizes adhered was 1.5% by weight relative to thefilaments. Thusly treated filament yarns were led to the first drier andsubjected to drying and shrinking simultaneously at a temperature of 170C.

Inside the drier there are provided combs spaced 40 cm. apart along thedirection of filament movement and crosswise to it. The combs have teethspaced 5 mm. apart. The filament yarns were separated from one anotherby the teeth of the combs and were prevented from mutal contact.

The filament yarns thus subjected simultaneously to drying and shrinkingtreatments, While maintaining a good alignment, were subsequentlytreated in a sizing bath having the following components.

Sizing agent: Percent Polyvinyl alcohol type Gosenol GIFOS 3 Polyacrylicacid derivative type Marposol Oiling agent:

Non-ionic surfactant Tomenolin F (trademark of Matsumoto Yushi KogyoK.K.) 1

and the total amount of sizes adhered was less than 10% by weightrelative to the filaments. Then the filament yarns were given in thesecond drier a longitudinal stretch to an extent less than that ofshrinkage produced in the aforementioned shrinking treatment and driedat a temperature of C.

Inside the drier, there are provided a comb placed 2 m. from the inletof the filament yarns, and 6 combs includ ing the first comb, arespaced, 1 m. apart along the direction of filament movement andcrosswise to it. The combs have the same shape as in the first drier.The filament yarns were separated from one another by tne teeth of thecombs and were prevented from mutual contact. Subsequently, thesefilament yarns were impregnated with a finishing oil comprising anon-ionic surfactant containing liquid parafiin TT-02l, and wound up ontake-ups at a speed of 60 rn./min.

Properties of filament yarns variously shrunk and sized in accordancewith the present invention are shown in Table 1.

TABLE 1 Percent shrinkage in the first drier... 0 5 10 15 19 19 Percentstretching in the second drier .1 0 1 3 0 4 Dry tensile:

Strength (g./d.) 3.9 3.8 3.6 3.6 3.1 3.4 glongation (percent)..- 8.010.7 15.0 16.8 28.0 21.3 no

Strength (g./d.) 1.1 1.9 2.1 2.2 3.1 2.5 Elongation (percent) 1.8 6.07.0 10.0 22.4 15.0 Residual shrinkage in boiling water (percent) 14 1211 10 4 6 Amount of sizing agent adhering to the fiber (percent) 3.2 5.22.9 7.0 4.1 6.2

1 2 Percent shrinkage in the first drier and percent stretching in thesecond drier are all based upon the swollen fibers which are stretchedwhile being heated.

These filament yarns remained well bundled with no trouble when spun,and were subjected to Slasher sizing without and difficulty. Further,No. 4 as such can be used as a warp, and No. 5 was applied as such toWarping and knitting tricot without any problem.

EXAMPLE 2 A spinning solution was fed under pressure by a gear pump at aspeed such that 40 denier filaments were obtained when the winding speedwas 60 -m./min. into a spinneret having 14 orifices, from which thesolution was extruded into an aqueous coagulating bath to formfilaments. These filaments were spun and stretched under heat in thesame way as in Example 1 to obtain swollen filament yarns, to which asizing agent solution having the same composition as in Example 1 wasthen applied. The sized filament yarns were shrunk 20% in the firstdrier and then stretched 2% in the second drier. After all, the filamentyarn had 3.5% of the sizing agent based on the weight of the filamentyarn. Said filament yarns were used without any trouble in warping andknitting tricot.

EXAMPLE 3 Filaments obtained by coagulating and washing in the same wayas in Example 1 so that filament yarns had 75 deniers (the number offilaments per unit is 15) when wound up at a speed of 70 m./min. werestretched 8 times in saturated steam. The thus obtained swollenfilaments was contacted with a sizing agent solution containing thefollowing components in a treating bath:

Percent Polyvinyl alcohol type size, Gosenol GH-17 (trademark of NihonGosei Kagaku Kogyo K. K.) 1 Acrylic size. Marposol pp-20 1 Oiling agent,non-ionic surfactant, Tomenolin F 0.5

so that the total amount of the size adhering to the filament was 2%based on the weight of filament. The resulting filaments were shrunk 18%in the same first drier as in Example 1, and then further contacted witha 2% solution of a polyvinyl alcohol type size, Gosenol GH- 17 so thatthe total amount of the two sizes adhering to the filament was 4%, andthen dried in the second drier while being stretched 1%. Well-bundledfilament yarns having good properties were obtained.

EXAMPLE 4 A spinning solution extruded under pressure through aspinneret having 60 holm of a diameter of 0.12 mm. so that 300 denieryarns were obtained when one unit consists of 60 spinnerets and thewinding speed was 40 m./min. was coagulated in the same way as inExample 1 to form a yarn every spinneret. The resulting filament yarnswere washed while maintaining spaces between filament yarns at 10 mm.,and then stretched 8 times in hot water.

These stretched swollen filament yarns were contacted with a 40%solution of a polyoxyethylene alkyl ether type non-ionic surfactant,Actinol R-100 to cause 1% of the oiling agent based on the weight of thefilament yarns to adhere to the filament yarns, and then dried in thefirst drier while shrinking them 5%. The resulting filament yarns werefurther contacted with a 2% solution of a vinyl acetate maleic acidcopolymer, Tamanori 8-400 (trademark of Arakawa Rinsan Kagaku Kogyo K.K.) to cause 1.5% of the size based on the weight of the filament yarnto adhere to the filament yarn, and then dried under no tension.

The thus obtained filament yarns remained well bundled before thesubsequent processing, while after being processed into textured yarns,they were made into yarns having a soft handle in which single filamentswere separated from the yarns.

EXAMPLE 5 Swollen filaments obtained by effecting the spinning andstretching under heat in the same way as in Example 1 so that 150 denierfilament yarns were obtained when wound up at a speed of 70 m./min. werecontacted with a melt solution of a solid parafiin, Sizecoat 50-A(trademark of Ipposha) having a melting point of 70 C. and containing anon-ionic surfactant to cause 1% thereof based on the weight of thefilament yarn to adhere to the filament yarns, and then dried in thisstate in the first drier while causing them to shrink 20%. The resultingfilament yarns were further contacted with a 2% solution of a polyvinylalcohol type sizing agent, Gosesize 8-100 (trademark of Nihon GoseiKagaku Kogyo K. K.) to allow 1.5% of the size based on the weight of thefilament yarn to adhere to the filament yarns, and thereafter driedwhile being stretched 2%. Sizecoat 50-A was applied to the filamentyarns in an amount of 2% based on the weight of the filament yarn.

Yarns obtained by processing the filament yarns according to the Falsetwist method were textured yarns having a kindly handle in which singlefilaments were separated from the yarns, though the yarns before theprocessing remained suitably bundled.

We claim:

1. A method of producing well aligned acrylonitrile polymer filament.Polymer yarns, comprising impregnating a hot, stretched and swollenacrylonitrile polymer filament yarn with an oiling agent having amelting point below C., drying the yarn while effecting a 5 to 20percent length-wise shrinkage thereof, impregnating the thusly shrunkenyarn with less than 10 percent by weight of a sizing agent, and dryingthe yarn while stretching same by 010%.

2. A method according to claim 1, wherein the oiling agent contains anon-ionic surfactant.

3. A method according to claim 1, wherein the sizing agent is selectedfrom the group consisting of polyvinyl alcohol, polyacrylic acid saltsand a copolymer of vinyl acetate and maleic acid.

4. A method according to claim 2, wherein the nonionic surfactant isselected from the group consisting of polyoxyethylene alkyl ethers,polyoxyethylene alkylphenols, polyoxyethylene alkyl esters and sorbitanalkyl esters.

5. A method of producing well aligned acrylonitrile polymer filamentyarns comprising impregnating a hot, stretched and swollen acrylonitrilepolymer filament yarn with less than 2 percent by weight of a firstsizing agent, drying the yarn while effecting a 5 to 20 percentlengthwise shrinkage thereof, impregnating the thusly shrunken filamentyarn with less than 10 percent by weight of a second sizing agent anddrying the yarn while stretching the same by 0-10 percent.

6. A method according to claim 5, wherein said sizing agents areselected from the group consisting of polyvinyl alcohol, polyacrylicacid salts and a copolymer of vinyl acetate and maleic acid.

7. A method of producing well aligned acrylonitrile polymer filamentyarns comprising impregnating a hot, stretched and swollen acrylonitrilepolymer filament yarn with a mixture of an oiling agent having a meltingpoint below 100 C., and less than 2 percent by weight of a first sizingagent based on the weight of the filament yarn, drying the yarn whileeffecting a 5 to 20 percent length-wise shrinkage, impregnating thethusly shrunken filament with less than 10 percent of a second sizingagent based on the weight of the filament yarn and drying the yarn whilestretching same by 0-10%.

8. A method according to claim 7, wherein the oiling agent contains anon-ionic surfactant.

9. A method according to claim 7, wherein the sizing agents are selectedfrom the group consisting of polyvinyl alcohol, polyacrylic acid saltsand a copolymer of vinyl acetate and maleic acid.

10. A method according to claim 8, wherein the nonionic surfactant isselected from the group consisting of polyoxyethylene alkyl ethers,polyoxyethylene alkylphenols, polyoxyethylene alkyl esters and sorbitanalkyl esters.

References Cited UNITED STATES PATENTS 2,587,619 3/1952 Hofmann 264-1992,692,875 10/ 1954 Weinstock 264-182 3,080,210 3/1963 Ucci 264-2063,099,517 7/1963 Hurky et a1 264182 3,147,322 9/1964 Fujisaki et al.264-182 DONALD J. ARNOLD, Primary Examiner.

